Mobile communication systems have evolved over the past ten years or so from the GSM System (Global System for Mobiles) to the 3G system and now include packet data communications as well as circuit switched communications. The third generation partnership project (3GPP) has now begun to develop a mobile communication system referred to as Long Term Evolution (LTE) in which a core network part has been evolved to form a more simplified architecture based on a merging of components of earlier mobile communications network architectures and a radio access interface which is based on Orthogonal Frequency Division Multiplexing (OFDM) on the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) on the uplink. The core network components are arranged to communicate data packets in accordance with an enhanced packet communications system.
At present mobile communications services are dominated by human to human (H2H) communications, that is, data which is transmitted by a human to another human or at least data that is transmitted for presentation to a human being. It is now recognised that there is a desire to cater for communications to and/or from machines which are referred to generally as machine type communications (MTC) or machine to machine (M2M) communications. MTC communications can be characterised as communicating data which has been generated from a source automatically, for example in response to some other stimulus, or event reporting some attribute of the machine, or some monitored parameter, or so-called smart metering. Human communications such as voice can be characterised as being communications requiring a communications session of some minutes with data being generated in bursts of several milliseconds with pauses there between. Human communications such as video can be characterised as streaming data at a substantially constant bit rate. In contrast MTC communications can generally be characterised as sporadically communicating small quantities of data although, it can be appreciated that there is also a wide variety of possible MTC communications.
As will be appreciated it is generally desirable to provide a mobile communications system and network which can operate efficiently, particularly although not exclusively in respect of the challenges presented by communicating data packets generated by MTC communications devices.